Ammonia, NH 3, is an alkaline gas and so turns damp red litmus paper blue. Ammonium ions (NH 4 +) – found in ammonium compounds such as ammonium chloride, ammonium nitrate and ammonium sulfate ...

The equation shows that ammonium chloride (a white solid) can break down to form ammonia and hydrogen chloride. It also shows that ammonia and hydrogen chloride (colourless gases) can react to ...